Magnetically operated electrical connector

ABSTRACT

An electrical connector having mating frusto-conical plug and socket members with electrical conducting rings and contact members providing full swivel contact and a magnetically operated circuit closing means functioning exclusively on movement of the members to mated position.

United States Patent 11 1 1111 3,816,679 Hotchkiss 1 June 11, 1974 [54]MAGNETICALLY OPERATED 2,573,920 11/1951 McLeod 200 5109 ELECTRICALCONNECTOR 3,144,527 8/1964 Tolegian ZOO/51.09 3459.725 12/1964 Dennis200/5109 [76] Inventor: John E. Hotchkiss, 451 Cedar Hill Dr San Rd aelCalif 94903 Primary Examiner-Harold Broome [22] Flled: July 23, 1973Attorney, Agent, or FirmWarren, Rubin, Brucker & 211 App]. 190.; 381,987chlckermg [52] [1.8. CI ZOO/51.09, 335/132, 335/202, [57] ABSTRACT [51]Int Cl Holt 33/00 An electncal connector having matmg frusto-comcal [58]Fieid 335/202 plug and socket members with' electrical conducting335/132 rings and contact members providing full swivel contact and amagnetically operated circuit closing [56] References Cited meansfunctioning exclusively on movement of the members to mated position,UNITED STATES PATENTS 2,298,172 10/1942 Rose et a1. ZOO/51.09 6 Claims,5 Drawing Figures /7 2 1 2 L 1' 1 t" J i .22 t ll 1 H 11 MAGNETICALLYOPERATED ELECTRICAL CONNECTOR The invention relates to detachableelectrical connectors such as the conventional appliance cord plug andconvenience wall outlet.

Conventional wall outlets have a pair of socket contacts chargednormally with a 120 volt differential. The immediate accessibility ofsuch charged contacts presents a potential hazard to manual engagementby metallic objects particularly in the hands of children. Also,engagement of the conventional plug in the wall outlet socket requires aprecise orientation of the plug prongs with respect to the socketopenings followed by the application of significant insertion force. Inmany instances, it is necessary to insert a line cord plug into a wallreceptacle which is behind and covered by a relatively heavy piece offurniture such as a desk or the like. Visibility of the wall outlet andaccess thereto may be difficult and awkward.

In accordance with the present invention and as a principal objectthereof, the plug and socket members incorporate a magnetically operatedelectric switch means which effects completion of the electric circuitto the contact members only after the plug and socket members areassembled. Accordingly, there is no voltage charge on the socketcontacts when the wall outlet is in an open unused condition, thusavoiding the potential danger of manual engagement above eluded to.

As another feature of the present invention, the plug is designed to beessentially self-homing into the wall receptacle, thus greatlyfacilitating the connection of the parts where visibility is impaired orspace restricted. It is accordingly a further object of the presentinvention that the plug and wall outlet parts only need be brought intoclose proximity when the magnetic couple provided in the structure willcause the units to move automatically together into proper fit andorientation for assured electrical connection.

Still another object of the present invention is to provide amagnetically operated electrical connector of the character describedwhich will provide a full swivel action ,between the plug and wallsocket while maintaining electrical continuity.

The invention possesses other objects and features of advantage, some ofwhich of the foregoing will be set forth in the following description ofthe preferred form of the invention which is illustrated in the drawingaccompanying and forming part of this specification. It is to beunderstood, however, that variations in the showing made by the saiddrawing and description may be adopted within the scope of the inventionas set forth in the claims.

Referring to said drawing:

FIG. 1 is a front elevation of a magnetically operated electricalconnector constructed in accordance with the present invention;

FIG. 2 is a cross sectional view of the connector taken substantially onthe plane of line 22 of FIG. 1;

FIG. 3 is a fragmentary back view of the wall receptacle;

FIG. 4 is a cross sectional view on a somewhat enlarged scale of theconnector taken substantially on the plane of line 4-4 of FIG. 2;

FIG. 5 is a cross sectional view of a modified form of the invention.

The electrical connector of the present invention comprises briefly plugand socket members 6 and 7 having concentric frusto-conical mating walls8 and 9; a pair of electric conducting rings 1] and 12 mounted inconcentric axially spaced positions on and exposed at the exteriorsurface of wall 8 and in axially spaced planes substantiallyperpendicular to the common axis of the frusto-conical parts; externalelectric conducting means, here line cord 13, connected to rings 11 and12; a pair of electric contact members 16 and 17 carried by the socketnumber 7 and exposed at the exterior surface 9 and being axially spacedto engage rings 11 and 12 when the plug and socket members are in matedposition; external electric conducting means 18 and 19 connected tocontact members 16 and 17, see FIG. 4; a magnet 21 carried by member 6;an armature 22 carried by member 7 for movement between unattracted andattracted positions and being displaced by magnet 21 to attractedposition upon positioning of the plug and socket members in matedposition, armature 22, here being connected to contact members 16 and 17so as to move them into engaged position with-rings 11 and 12 as thearmature is displaced to attracted position. Contact members 16 and 17thus form the moving part of an electric switch, and in the absence ofplug 6, these contact members will be withdrawn into the wallreceptacle. A leaf spring 26 secured to the armature and housing 27 ofthe wall receptacle serves as a biasing means for normally holdingcontacts 16 and 17 in a relatively retracted position.

Rings 11 and 12 may be conveniently cast or molded into the body of plug6 made of thermoplastic or other electric insulation material; and theconductor ends of line cord 13 may be braised or otherwise secured tothe plug with the cord molded in place. Alternatively, conventionalscrew terminals may be provided on plug 6 connected to rings 11 and 12for connection of the conductor ends of line cord 13.

The wall receptacle unit 7 is here in the form of an adapter which maybe added to the conventional wall outlet. Accordingly, socket member 7is here provided with two laterally spaced pairs of prongs 18 and 19which are spaced for insertion into the conventional double socketedwall outlet. Alternatively, the contact prongs 18 and 19 may be deletedand screw terminals provided for direct wall installation in the mannerof the conventional duplex outlet. Also, while two socket units areprovided in conformity with conventional practice, it will be understoodthat the two are of identical construction and a description of one willsuffice for both. With reference to FIG. 2, no plug is shown mounted inthe left-hand socket and accordingly the movable contacts 16-17 areretracted and the armature 22 in a lower position than the correspondingposition of these parts in the right-hand socket structure where a plug6 is shown mounted in place. In such case, magnet 21 has drawn armature22 upwardly against the bias of leaf spring 26 and has advanced contactmembers 16 and 17 into engagement with rings 11 and 12 as illustrated inFIG. 4.

Preferably, and here best shown in FIGS.'3 and 5, prongs 18 and 19 areconnected to contacts 16 and 17 by stationary switch contact members 28and 29. Prongs l8 and 19 may be formed from electric conducting plates32 and 33 secured as by screws 34 and 35 in the socket housing 27.Contact members 28 and 29 are here connected at one end to plates 32 and33 and extend laterally and axially therefrom, as seen in FIG. 4, aroundthe base ends 37 and 38 with the distal ends 41 and 42 of members 28 and29 positioned in engagement with contact ends 37 and 38 in the attracted(raised) position of armature 22, and in spaced electric circuit openposition from contact portions 37 and 38 in the unattracted (lowered)position of armature 22. Contact members 16 and 17 are here secured toan insulation plate 43 which is positioned between contact members 16and 17 and plates 32 and 33 in the unattracted armature position, thus,opening the electric circuit between prongs 18 and 19 and contactmembers 16 and 17. On insertion of plug 6 and attendant movement ofarmature 22 to attracted position, as seen in FIG. 4, the electricalswitch defined by parts 37-41 and 38-42 is closed thereby completing theelectric circuit to contact rings 11 and 12.

As will be observed, contact members 28 and 29 in their entirety areenclosed within, and protected from accidental external physical contactby, socket housing 27. It will further be noted that the free upstandingends 41 and 42 of contact members 28 and 29 are by reason of the loopedshape of the contact members supported for resilient axial displacementby contacts 37 and 38 as the latter move with the armature to attractedposition. Consequently, a firm electrical contact will be establishedbetween switch contact portions 37-41 and 3842 in advance of themovement of contact members 16 and 17 into engagement with contact rings11 and 12 on the plug.

As will be observed from FIGS. 2 and 4, the magnet and armature areaxially opposed for providing an axially aligned magnetic force drawingthe plug and socket members into mated position as well as the rings andcontact members into engaged position, and furthermore, the contactpressure between the electric parts is a function of the magnetic force.Thus, when the plug 6 is brought into close proximity to socket 7, themagnetic attraction will provide a self-homing force causing the plug tosnap into a proper seated position in the socket and at the same timeeffect a closure of the electric circuit as above described.Accordingly, to effect the connection of the plug in the socket, it isonly necessary to depend plug 6 on cord 7 into registration with thesocket following which the self-homing attachment will take place. Onlya very limited space through which to lower the plug is required forthis purpose. Also, since perfect electric contact is made regardless ofthe angular orientation of the plug with respect to the socket, no otheralignment of the parts needs be observed. In this connection, it will benoted that plug 6 may be rotated about its common axis with socket 7through 360 while maintaining electrical continuity between contactmembers 16 and 17 and rings 11 and 12, thus affording full swivel actionof the plug while maintaining full current flow. While the magnet andarmature may be optionally incorporated in either the plug or socketmember, I prefer to mount magnet 21 in plug member 6 with a magnet poleface 31 disposed centrally at the reduced end of the plug so as toprovide for minimum spacing between the magnet pole face 31 and armature22 when the plug is in attached position as seen in FIG. 4.correspondingly, I prefer to mount armature 22 in the socket centrallyof the reduced end thereof for axial movement to pole face 31.

A modified form of the invention is illustrated in FIG. 5 of the drawingwherein electromagnetic means is provided for augmenting the magneticforce of magnet 21a. This means may comprise a magnetic field winding 36connected to the electric circuit for automatic energizing of theelectromagnetic means upon closing of the electric circuit by themagnetically operated switch. Magnet 21a is designed to have sufficientresidual, permanent, magnetism to effect the initial displacement ofarmature 22 as above described so as to close the electric circuitfollowing which the electromagnetic means will be energized to increasethe contact pressure. As here shown, winding 36 directly surrounds amagnetic core 21a and has its opposite ends connected to contact rings11a and 12a.

I claim:

1. An electrical connector comprising:

plug and socket members having concentric frustoconical mating walls;

a pair of electrical conducting rings mounted in concentric axiallyspaced positions on and exposed at the exterior surface of one of saidwalls and in axially spaced planes substantially perpendicular to theaxis of said last named wall;

external electric conducting means connected to said rings;

a pair of electric contact members exposed at the exterior surface ofthe other of said walls and spaced axially from each other to engagesaid rings when said plug and socket members are in mated position;

external electric conducting means connected to said contact members;

electric switch means connected for completion of an electric circuitthrough said rings and contact members and having a switch part movablebetween circuit closing and circuit opening positions;

means biasing said part to circuit open position;

a magnet carried by one of said members;

an armature carried by the other of said members for movement betweenunattracted and attracted positions and being displaced by said magnetto attracted position upon positioning of said plug and socket membersin mated position; and

means connecting said armature and switch part for movement of thelatter to circuit closed position upon movement of said armature toattracted position.

2. A connector as defined in claim 1:

said magnet and armature being axially opposed and exerting an axiallyaligned magnetic force drawing said members into mated position and saidrings and contact members into engaged position with the contactpressure therebetween being a function of said magnetic force.

3. A connector as defined in claim 2:

one of said contact members being mounted for axial reciprocation intoand out of engagement with one of said rings and being connected to saidarmature for displacement into ring engaged postion by said magneticforce.

4. A connector as defined in claim 3:

said magnet being mounted on said plug member and having a pole disposedcentrally at a reduced plug end inserted into said socket member; and

force of said magnet.

6. A connector as defined in claim 4:

a magnetic field winding surrounding said magnet and connected to saidcircuit and energized upon closing of said circuit and augmenting thefield strength of said magnet when said winding is energized.

1. An electrical connector comprising: plug and socket members havingconcentric frusto-conical mating walls; a pair of electrical conductingrings mounted in concentric axially spaced positions on and exposed atthe exterior suRface of one of said walls and in axially spaced planessubstantially perpendicular to the axis of said last named wall;external electric conducting means connected to said rings; a pair ofelectric contact members exposed at the exterior surface of the other ofsaid walls and spaced axially from each other to engage said rings whensaid plug and socket members are in mated position; external electricconducting means connected to said contact members; electric switchmeans connected for completion of an electric circuit through said ringsand contact members and having a switch part movable between circuitclosing and circuit opening positions; means biasing said part tocircuit open position; a magnet carried by one of said members; anarmature carried by the other of said members for movement betweenunattracted and attracted positions and being displaced by said magnetto attracted position upon positioning of said plug and socket membersin mated position; and means connecting said armature and switch partfor movement of the latter to circuit closed position upon movement ofsaid armature to attracted position.
 2. A connector as defined in claim1: said magnet and armature being axially opposed and exerting anaxially aligned magnetic force drawing said members into mated positionand said rings and contact members into engaged position with thecontact pressure therebetween being a function of said magnetic force.3. A connector as defined in claim 2: one of said contact members beingmounted for axial reciprocation into and out of engagement with one ofsaid rings and being connected to said armature for displacement intoring engaged postion by said magnetic force.
 4. A connector as definedin claim 3: said magnet being mounted on said plug member and having apole disposed centrally at a reduced plug end inserted into said socketmember; and said armature being mounted in said socket centrally of areduced base thereof and for axial movement to said pole in the matedposition of said plug and socket members.
 5. A connector as defined inclaim 1: electro magnetic means having a winding connected to saidcircuit and energized upon closing said circuit and disposed foraugmenting the magnetic force of said magnet.
 6. A connector as definedin claim 4: a magnetic field winding surrounding said magnet andconnected to said circuit and energized upon closing of said circuit andaugmenting the field strength of said magnet when said winding isenergized.